Answer:1176
Explanation:
Number of male students: 2940*(60/100)=1764
So the number of female students would be:
2940-1764=1176
Answer:
Try:
1. How many atoms are in 6.5 moles of zinc?
6.5 moles 6.02 x 1023 atoms = 3.9 x 1024 atoms
1 mole
2. How many moles of argon are in a sample containing 2.4 x 1024 atoms of argon?
2.4 x 1024 atoms of argon 1 mole = 4.0 mol
6.02 x 1023 atoms
3. How many moles are in 2.5g of lithium?
2.5 grams Li 1 mole = 0.36 mol
6.9 g
4. Find the mass of 4.8moles of iron.
4.8 moles 55.8 g = 267.84 g = 270g
1 mole
Explanation:
i think i did it about right..?? :-(
Answer: Option A) 83.9g
Explanation:
KCl is the chemical formula of potassium chloride.
Given that,
Amount of moles of KCl (n) = ?
Volume of KCl solution (v) = 0.75L
Concentration of KCl solution (c) = 1.5M
Since concentration (c) is obtained by dividing the amount of solute dissolved by the volume of solvent, hence
c = n / v
make n the subject formula
n = c x v
n = 1.5M x 0.75L
n = 1.125 mole
Now given that,
Amount of moles of KCl (n) = 1.125
Mass of KCl in grams = ?
For molar mass of KCl, use the molar masses of:
Potassium, K = 39g;
Chlorine,Cl = 35.5g
KCl = (39g + 35.5g)
= 74.5g/mol
Since, amount of moles = mass in grams / molar mass
1.125 mole = m / 74.5g/mol
m = 1.125 mole x 74.5g/mol
m = 83.81g
Thus, 83.9 grams of KCl are needed to prepare 0.750 L of a 1.50 M solution in water
Answer:
1-b
2-weaker(option is incorrect)
3-a
Explanation:
1-b because iodine is more electronegative because of this negative on iodine will be more stable as negative charge on more electronegative element is more stable.
2-weaker as size of Te (Tellurium) is greater than S (sulphur) so bond length of H-Te is larger than H-S and therefore bond energy will be lesser and can easily give hydrogen in case of H-Te. as bond energy is inversly proportional to bond length.
3-a hydrogen has more negative electron affinity so hydrogen will have -1 charge and it will behave as a electron donar atom that is basic not acidic hence NaH is not acidic.
It is typically formed by the evaporation of salty water (such as sea water) which contains dissolved Na+ and Cl- ions. One finds rock salt deposits ringing dry lake beds, inland marginal seas, and enclosed bays and estuaries in arid regions of the world
